45 research outputs found
Genetic diversity and relationship assessment among mulberry (Morus spp) genotypes by simple sequence repeat (SSR) marker profile
Mulberry (Morus L.) is essential for sericulture industry as the primary source of food for silkworm Bombyx mori L. In India, long tradition of practising sericulture includes the use of a large number of indigenous cultivars. Since knowledge on genetic divergence of these cultivars/varieties is imperative for conservation and gainful utilization, simple sequence repeat (SSR) profiling was employed to assess genetic relatedness among 17 mulberry genotypes maintained in the Germplasm Bank of Temperate Sericulture Institute, SKUAST Kashmir, Mirgund. Six SSR primers were utilised which generates 17 alleles among the genotypes. The polymorphism information content (PIC) value varied from 0.260 (MulSTR3) to 0.623 (MulSTR4), with an average of 0.438 per locus. The highest similarity value of 0.92 was observed between Lemoncina and Kanva-2, as compared to the lowest similarity coefficient of 0.15 was between SKM-48 and Chinese white. Clustering of the genotypes was done with unweight pair group method using arithmetic average (UPGMA) which generates five clusters. Cluster-2 contained maximum (six) genotypes.Keywords: Clustering, genetic relatedness, mulberry, SSRAfrican Journal of Biotechnology Vol. 12(21), pp. 3181-318
Participatory rural appraisal and farmers’ perception about common bean varieties in temperate Kashmir
Present investigation was undertaken during 2012 to 2014 in which 54 genotypes, both pole and bush type of Common beans (Phaseolus vulgaris) were selected among a number of germplasm lines, land races and research material in order to generate information on the farmer’s’ perception about the Common bean varieties. Participatory rural appraisal was conducted in 32 villages of Kashmir through a broad questionnaires comprising of questions pertaining to the socio-economic conditions, farming systems, production constraints and varietal preferences of the common bean. The Participatory Rural Appraisal results revealed that common bean is generally grown as a rainfed crop (70 %) and is intercropped with maize/ potato/vegetable and merely as sole crop (20.66 %). Low yielding varieties and diseases (68.27 %) are considered as major challenges in the success of common bean crop, while as red colour with kidney shaped types (50 %) are highly being preferred as a pulse crop. The exercise of Participatory Rural Appraisal was carried out to generate basic information by assessing the need based constraints and devise the target breeding approach, by taking into consideration all constraints and also devise future breeding programme. A successful PRA provides the information needed to specify the characteristic in a new variety regarding its physical environment and the existing varietal diversity. For a breeding program, well applied Participatory Rural Appraisal techniques or customer profiling results in better client orientation and makes possible efficient goal setting or product design. Successful PRA provides everything that could be included in the full design specification of a new crop variety
Breeding strategies for improving growth and yield under waterlogging conditions in maize: A review
Waterlogging, caused by flooding, excessive rains and poor drainage is a serious abiotic stress determining crop productivity worldwide. Maize (Zea mays L) is a basic food grain in many areas and several cultures and is culti- vated under much diverse agro-climatic zones extending from subtropical to cooler temperate regions. Therefore, the crop remains open to varied types of biotic as well as abiotic stresses. Among various abiotic stresses, water- logging is one of the most important constraints for maize production and productivity. Breeding for improved wa- terlogging tolerance includes modification of plant morphology, use of tolerant secondary traits and development of resistant varieties through conventional breeding and biotechnological approaches. A successful programme in conventional breeding should involve the integration of several criteria into one selection index and also successful breeding programmes for improved tolerance to submergence stress frequently combine two or more breeding strategies. Marker assisted selection (MAS) is an effective approach to identify genomic regions of crops under stress and construction of molecular linkage maps enable carry out pyramiding of desirable traits to improve sub- mergence tolerance through MAS
Transgenesis: An efficient tool in mulberry breeding
Genetic engineering is the most potent biotechnological approach dealing with transfer of specially constructed gene assemblies through various transformation techniques. Tools of recombinant DNA technology facilitated development of transgenic plants. The plants obtained through genetic engineering contain a gene or genes usually from an unrelated organisms, and are known as transgenic plants. The combined use of recombinant DNA technology, gene transfer methods and tissue culture techniques has led to the efficient transformation and production of transgenics in a wide variety of crop plants. In fact transgenesis has emerged as a novel tool for carrying out “single gene breeding” or transgenic breeding of crop plants. Identification, isolation and cloning of resistant genes is the prerequisite for development of transgenic plants for disease resistance. Identification of resistance genes on the basis of amino acid sequence, conservation enables plant breeder to monitor resistance gene segregation using appropriate DNA probe intend of testing progeny for disease resistance and susceptibility. Significant developments in plant genetic modification have been achieved in the last 15 years. Some of the success include herbicide tolerant corn, cotton, soyabeen and papaya; virus resistant corn, potato, cotton among others. In mulberry, little work has been carried out at Delhi University (south campus). They have developed drought and salinity tolerent transgenic mulberry through Agrobacterium mediated transformation. The overexpression of HVA1 gene from barley generates tolerence to salinity and water stress in transgenic mulberry (Morus indica).Keywords: Transgenic plant, mulberry, resistance, salinity
A Novel Application of Quantum Speed Limit to String Theory
In this work, we investigate the implications of the concept of quantum speed
limit in string field theory. We adopt a novel approach to the problem of time
on world-sheet based on Fisher information, and arrive at a minimum time for a
particle state to evolve into another particle state. This is done using both
the Mandelstam-Tamm bound and the Margolus-Levitin bound. This implies that any
interaction has to be smeared over such an interval, and any interaction in the
effective quantum field theory has to be non-local. As non-local quantum field
theories are known to be finite, it is expected that divergences should be
removed from effective quantum field theories due to the quantum speed limit of
string theory.Comment: 9 page
Genotypic and morphological diversity analysis in high altitude maize (Zea mays L.) inbreds under Himalayan temperate ecologies
The present investigation was carried out to generate information on genetic divergence of maize (Zea mays L.) inbreds and to identify elite lines to develop potential hybrids for high altitude ecologies. Data were recorded for thirteen (13) quantitative traits viz. germination (%), root depth, shoot length, days to 50 % pollen shed, days to 50% silking, plant height, ear height, ear length, ear girth, number of kernels per row, 100 seed weight, grain yield per plant. The tested genotypes expressed significant variability with high estimates of heritability (broad sense) for all the traits revealing that these traits are amenable to genetic improvement. Grain yield per plant exhibited positive and significant correlation with plant height, ear height, ear width, number of kernels per row, number of kernel rows and 100 seed weight at both the levels which exhibit a strong possibility for improvement of grain yield per plant by selection for these traits. Genetic divergence based on thirteen quantitative traits grouped thirty maize inbred lines into four clusters as per Mahalanobis D2 analysis employing Tocher’s method which revealed wide diversity in elite genotypes owing to the involvement of diverse parental lines in the hybridization programme. Grain yield per hectare was the main factor contributing to total divergence (41.16%) which needs to be considered for highlighting clusters to be chosen for the purpose of further selection
Stable relocation of the radial head without annular ligament reconstruction using the Ilizarov technique to treat neglected Monteggia fracture: two case reports
<p>Abstract</p> <p>Introduction</p> <p>A Monteggia facture dislocation is not an uncommon injury, and the diagnosis can often be missed. Long-term follow-up of untreated Monteggia fracture dislocations reveals development of premature arthritis, pain, instability, and loss of pronation and supination. Methods involving annular ligament reconstruction require post-operative immobilization and use of transcapitellar pinning for maintenance of reduction, and thus a delay in rehabilitation. The literature reports satisfactory results with methods that involve ulnar osteotomy and open reduction of the radial head without annular ligament reconstruction. We used the Ilizarov method in two cases with neglected Monteggia fracture dislocations to stably reduce the radial head without open reduction and annular ligament reconstruction.</p> <p>Case presentation</p> <p>We report two cases of neglected Monteggia fracture dislocation, in two Kashmiri boys aged four and six years. Using ulnar osteotomy with distraction osteogenesis, we were able to relocate the radial head gradually and maintain the reduction without a requirement for open reduction and annular ligament reconstruction.</p> <p>Conclusion</p> <p>Distraction lengthening and hyperangulation in different planes by use of the Ilizarov technique effectively reduces the radial head without open reduction and annular ligament reconstruction.</p
Review article: Quality protein maize (QPM): Genetic
Cereals are the only source of nutrition for one-third of the world’s population especially in
developing and underdeveloped nations of Sub-Saharan Africa and South-east Asia. The three
major cereals, rice, wheat and maize constitute about 85% of total global cereals production
amounting to about 200 million tonnes of protein harvest annually at an average of 10% protein
content, out of which a sizeable proportion goes into human consumption (Shewry, 2007). A major
concern in case of developing nations is that in most cases, a single cereals crop is the major food
staple and as such the nutritional profile of cereal crops assumes great significance. Grain protein
content of cereals has a very narrow range with rice (5.8-7.7%), maize (9-11%), barley (8-15%) and
wheat (7-22%) as reported by various workers. In many developing countries of Latin America,
Africa and Asia, maize is the major staple food and often the only source of protein. At global level,
maize accounts for 15% of proteins and 20% of calories in world food diet. But unfortunately, the
nutritional profile of maize is poor as it is deficient in essential amino acids such as lysine,
tryptophan and methionine due to a relatively higher proportion of prolamines in maize storage
proteins which are essentially devoid of lysine and tryptophan. The reason concerning this is that
lysine, tryptophan and threonine are the limiting amino acids in human beings and non-ruminants.
Maize is also an important component of livestock feed especially in developed nations where 78%
of total maize production goes into livestock feed. Therefore, breeding strategies aimed at
improving the protein profile of maize will go a long way in reducing prevalence and persistence of
malnutrition in developing world